Hydraulic apparatus



m 9 6 'F.J.WRIGHT 2,401,397

" HYDRAULIC APPARATUS Filed June 19,- 1943 3 snets-snee' 1 INVENTOR FREDB=YLWRIGHT Mia/Mm ATTORNEY F. Jr WRIIGHQT 2,401,397

June 4, 1946.

Filed June 19, 1945 I i Q ATTORNEY Patented June 4, 1946 2,401,397 7 HYDRAULIC APPARATUS Fred J. Wright, Columbus, Ohio, assignor to The Denison Engineering Company, Columbus, Ohio, a corporation of Ohio Application June 19, 1943, Serial No. 491,503

2 Claims.

This invention relates to hydraulic equipment and is particularly directed to valve mechanism for controlling fluid flow through a system in which fluid pressure energy translating devices are employed.

An object of this invention resides in the provision of an improved control valve by means of which a highly accurate control may be maintained over power units or similar devices arranged in a hydraulic system.

Another object of the invention resides in the provision of a valve having means which may be set to provide a flow of fluid at a predetermined volume for a given pressure and other means which will automatically vary the volume to maintain the pressure so that in the event a hydraulic operating unit, disposed in the system in which the valve is connected, is relieved of its load, violent action will not take place but the unit will be maintained under control at all times.

A further object is the provision'of a valve having a body with an internal passage extending from the inlet to the outlet of the valve and arranging a pair of flow controlling devices in the internal passage, one of the devices being manually set to permit fluid fiow through the passage while the other device operates automatically in response to fluid pressures in certain portions of the passage to vary the volume of fluid flowing therethrough. I 1 Another object is the provision of a valve mechanism which can be used to control the action of a motor operated by fluid pressure whereby the motor will operate at a substantially constant rate whether under load or merely idling, the valve having a throttle device for use as the master control unit and a pressure operated valve to serve as a secondary control unit whereby to increase fluid flow when'power is I required and decrease the flow when power is not needed.

Further objects and advantages of the present invention will be apparent from the following description, reference being had tothe accompanying drawings wherein a preferred form of embodiment of the invention is clearly shown.

Fig. 4 is a vertical transverse sectional view control valve includes sections 2| and 22 suitably secured together to form a main body. The sections are preferably formed by casting the same from metal. Section 2| is provided with a socket 23 and each section is provided with passages 24 and 25, the respective passages being joined when the sections 2| and 22.are connected. The section 2! includes an inlet port 26 which communicates with the passage 24 and an outlet port 21.

In the embodiment of the invention illustrated, the valve is attached to a ported plate or wall 28 forming a part of the hydraulic equipment with which the control valve is associated. The plate 28 has openings and 30 with which the inlet and outlet ports, respectively, of the valve communicate, suitable sealing members 3| being provided to prevent leakage around the ports. The section 2| includes a third port 32 which is closed by the plate 28 when the valve is used in the manner set forth in this application. The function of the port 32 is set forth in-my copending application Serial No. 491,502, filed June 19, 1943 (Doc. 558) and since it-is not employed in this embodiment of the invention, further discussion thereof is believed'to be unnecessary.

Communication between the passages 24 and 25 and the outlet port 21 is controlled by a barrel valve 33 which is received for rotary movement in the socket 23. This valve has a-pair of longitudinally spaced annular grooves 34 and 35 which register with the passages 24 and 25, respectively,

to permit fluid flow through the passages and around the valve 33. As shown in-Fig. 3, one side of the barrel valve 33 is relieved where it registers with the outlet port 21, to form, with the socket 23, a crescent shaped chamber 36. This chamber 36 communicates through a po t 35a.

' 25 and the passage 31 so that the fluid can flow from the passage 25 through the ports 39, the passage 31 and into the'crescent shaped chamber 36.

When it is desired to permit fluid to flow from this chamber 35, the barrel valve is rotated until one end of the chamber connects with the outlet port 21. The degree of communication or the size of the opening between the chamber 35 and the port is controlled by the degree of rotation of the valve 33. To effect this turning movement, the upper end of the valve 33 is provided with a reduced stem 39A which extends through a cap 40 carried by the upper end of the section 2|. This stem has an operating handle 4| keyed thereto as at 42.- The handle 4i is secured to the stem by a nut 43 received by the reduced threaded end 44 of the stem 39A.

The cap 40, by engaging a shoulder at the lower end of the stem 39A serves to retain the valve 33 in position in the socket 28 but permits free turnme movement thereof. Fluid loss around the stem 39A is prevented by locating a packing ring 45 in the cap 40 immediately under the operating handle 4|. The cap 40 is also provided with a stop pin 45 which projects into a recess in the handle and serves, through engagement with the ends of the recess, to limit the degree of rotation of the handle 4 2ancl the valve 33.

As illustrated in Fig. l, the passages 24 and 25, in the section 22, communicate with spaced chambers 41 and 48, respectively, which are connected b a socket 49 extending vertically through the section 22, The upper and lower ends of this socket are closed by caps 50, each of which is provided with a central recess 5| and a channel 52 extending laterally therefrom a relatively short distance. The cap at the upper end of the section 22 is so positioned that the outer end of the channel 52 registers with the upper end of a passage 53 formed in the section 22 and extending to the passage 25. The passage 53 and channel 52 establish communication between the upper end of the socket 49 and the passage 25. Referrin to Fig. 2, it will be seen that the cap at the lower end of the section 22 is so placed that the outer end of the channel 52 therein communicates with the lower end of a vertically extending passage 54 which connects at its upper endwith a horizontal passage 55, shown more clearly in Fig. 3, the latter, in turn, connecting with a similar passage 55 formed in the section 2|. The passage 56 extends into the section 2| from the face to which the section 22 is attached and at its inner end, is connected by a lateral extension 51' with the outlet port 21. At the point of connection of the passages 55 and 56, a plug 58 ispositioned in passage 53, this plug having a reduced orifice 59 to restrict the flow of fluid through these passages and prevent the transmission of surging pressures to the socket 49. The socket 49 in the section 22 is provided for the reception of a sliding spool valve 56- which has an annulargroove 5| located intermediate of its length in the outer surface, This groove permits communication between the chambers 41 and 48 when the spool is in certain positions of longitudinal movement in the socket 49. The annular groove 6| is disposed in closer relation to the lower end of the spool in order to provide a shoulder 52 in rela-.

tively close relation to the lower wall of the chamber 48 when the spool is in its uppermost position where it is normally maintained by a coil spring 63 disposed between inner end of a socket 54 provided in the spool and the bottom of the recess 5| formed in the lower cap 53. This coil spring serves to urge the spool toward the upper end of the socket 49 whereby the annular groove 5| will provide communication between the chambers 41 and 48. Of course, when the mechanism is constructed as shown, the

selected must have sumcient strength to overcome the weight of the spool valve 50 to accomplish this purpose.

The spool valve shown has its'upper end provided with a socket 65 which serves to reduce the weight of the spool and also as a chamber !or the reception of a coil spring in another adaptation of the valve. When the valve is used in a hydraulic system, the port 26 receives liquid under pressure from a pump or other source of fluid supply.

While the barrel valve 33 is maintained in the position shown in the drawings, the liquid can flow only from the port 28 through the passage 24 to the chamber 41 and through the groove 5| to the chamber 48 from which it will flow into the passage 25. Since the valve 33 is positioned to prevent liquid flow from the chamber 36 to the outlet port, the fluid will remain in the passages 25 and 31 at the pressure prevailing in port 26.

.The passage 53, the channel 52, the recess 5| and socket will be filled with liquid. Since this liquid is under pressure, a downward force will be exerted on the wall at the lower end of the socket 65 and on the upper end of the spool valve 60. When the hydraulic system is in operation,

the liquid pressure is suflicient to overcome the resistance of the spring 53 and expel any fluid in the socket 49 below the valve through passages 52, 54, 55, 55 and 51 to the outlet port. The valve 60 will move downwardly until the shoulder 62 reaches the lower wall of the chamber 48 and interrupts communication between the passages 24 and 25.

The control valve has many uses, one of which is togovern the flow of fluid under pressure to a* fluid motor employed to drive machinery. When so employed, the outlet port 21 or the port 30 in plate 28 is connected by a suitable pipe with the inlet of the fluid motor, not shown; When the valve 33 is adjusted to permit the flow from the chamber 36 tothe port 21 and from the latter to the fluid motor, the lower end of the socket 48 will contain liquid under pressure equal to the pressure in port 21. If the resistance to the flow of fluid through the motor is sufficient to cause the'pressure in the outlet port 21 to increase until it is substantially equal to the pressure in the inlet port 26, the fluid pressure at the upper and lower ends of the spool valve will be equalized and the spring 63 will move the spool valve 69 to the position wherein maximum communication is established between passages 23 and 25. In the event the fluid pressure in the outlet port is decoil spring 53 creased, either by the fluid motor gaining momentum or the load thereon being decreased, the pressure in the lower end of the socket 49 will be correspondingly decreased and a pressure differential on the upwardly and downwardly facing surfaces of the spool valve 66 will exist, the greater pressure being applied to the upwardly facing surfaces. This pressure will cause the valve 50 to move toward a closed position whereby fluid flow will be decreased until only sumcient fluid flows to operate the motor at the desired rate. As the fluid pressures-at opposite ends of the spool valve 50 again approach equalization, due to a load being placed on the motor, the spool valve 60 will be moved by the spring 63 to increase fluid flow through the valve.

From the foregoing, it will be apparent that a control valve unit has been provided which is particularly adapted to the control of hydraulic systems employing liquid pressure energy translating devices, due to the fact that it will prevent damage to such devices by preventing their tend- 5 encies to operate too rapidly after overcoming starting loads or aiter being relieved of load durv ing operation; The control valve 33 may be set to provide for fluid flow to the fluid motor at a predetermined rate for a given pressure on the liquid supplied to the control unit which rate is calculated to cause the fluid motor tooperate in the desired manner. It the resistance to the opera .variation' in resistance. It the resistance increases, the pressure on the liquid in the conduit between the control valve and the'motor will build up vand this increased pressure will be transmitted through the passages 57, $8, 55, 54

and B2 to the underside of the spool valve 60. This increased pressure under the spool valve will move the same toward a fully open position to increase the flow oi fluid to passage 25. This additional fluid flow will increase the pressure in passage '25 and more fluid will then flow through the control valve unit although the valve setting oi valve 33 has not been changed.

when the load on the motor decreases, the resistanee to fluid flow away from the control unit will be decreased and the pressure on the liquid in the outlet port 21 will tall. This reduction in pressure in the outlet port will decrease the pressure beneaththe spool valve 60 and the pressure on the fluid above the valve will cause the same i to move toward a closed position and reduce the flow oi fluid into passage 28. This action will decrease the flow of fluid through the central unit and the motor will be While the form oi embodiment oi the present invention as herein disclosed constitutes a preferred form, it is .to be understood that other; forms might be adopted, all coming within the scope oi theclaims which follow. I

I claim: r I

1. In a control valvefor hydraulic systems, a body having a socket and internal passages spaced longitudinally thereof, one of said passages terminating in an outlet port, a valve plug disposed in said socket to control fluid flow between said passages, said plug having an eccentric portion in registration with one 0! said passages said eccentric portion being of smaller diameter. than said plug and having a portion of its surface iorming a continuous surface or the plug in order to cooperate as a variable orifice valve with the socket wall and said passage, and a passage in said plug connecting another of said passages in said body with said oriilce. A 2. In a control valve for hydraulic systems, a body having a socket and internal passages spaced longitudinally thereoi, one of said passages tor minating in an outlet port. a valve pl g disposed in said socket to control fluid flow between said passages, said plug having an eccentric portion in registration with one of said passages said eccentric portion being 0! smaller diameter than said plug and having a portion or its sm'iaoe iorming a continuous surface of the plug in-order to cooperate as a variable oriiice valve with the socket wall and said passake. a passage in said plug connecting another oi said passages in said operating means ior prevented from operating as said plug disposed exteriorly oi said body.

I FRED J. WRIGHT.

bocLv with said orlflce, and 

